1. Field of the Invention
The present invention relates to an organic light emitting diode and a display device using the same. More particularly, the present invention relates to an organic light emitting diode which is suitably applied to an OLED display and a display device using the same.
2. Description of Related Art
Organic light emitting diode (OLED) is a self-luminous device which has advantages of wide viewing angles, high contract, rapid response, and high brightness, and may provide a visual light with a wide range.
A basic structure of a conventional OLED includes an anode, an organic layer and a cathode which are sequentially disposed on a substrate. When electrons and holes from the cathode and the anode are respectively transported into the organic layer and are recombined with each other in the organic layer, light is emitted. Due to the difference between the refractive indexes of materials of the OLED and the difference between the refractive indexes of the OLED and the environment, most emitted light is trapped in the OLED and cannot emit to the outside, resulting in a decrease of the light extraction efficiency of the OLED. Therefore, for improving the light extraction efficiency of the OLED, many researchers made efforts to dissolve such problem by, for example, using a micro lens array (MLA), forming a specific crystalline pattern by photolithography and etching, or coating a light scattering layer on a side of a transparent electrode. However, the above-mentioned methods may cause the product cost increased due to a complicated process and the OLED degraded due to a solvent volatilization process. Thus, the above-mentioned methods are hard to wildly apply to all kinds of OLED.
Accordingly, there is a need to develop an OLED which is manufactured by a simple process and has high light extraction efficiency.